Table 1.
Some methodologies for removal of Pb2+ and Cu2+ from water.
| Ions | Method | Operation Condition | Removal Efficiency | Advantages/Disadvantages |
|---|---|---|---|---|
| Cu2+, Pb2+, Zn2+ | Chemical precipitation | Cu2+ = 0.018 mM, Pb2+ = 2.3 mM, Zn2+ = 1.34 mM; precipitant, H2S; pH = 3.0 | Cu2+ (100%), Pb2+ = (92%), Zn2+ = (94%) | Most widely used process in industry; it is relatively simple and inexpensive/it generates large volumes of relatively low density sludge; sulfide precipitants can result in the evolution of H2S [10,11]. |
| Cu2+, Cr3+, Pb2+, Zn2+ | [metal] = 100 mg·L−1 precipitant, CaO; pH = 3.0 | >99% | ||
| Cu2+ | Ion exchange | Cu2+ = 100 mg·L−1; Resin-supported polyethyleneimine; pH = 5.0 |
>99% | High treatment capacity, high removal efficiency and fast kinetics/leaching during operation, highest costs for synthetic resins [9,11,12] |
| Pb2+; Cu2+ | Cu2+ = 25 mg·L−1; Resin-THQSA; pH = 4.5 |
60–90% | ||
| Cu2 | membrane separation—Electrodyalisis | Cu2+ = 100 mg·L−1; membrane: packed beds of graphite powder; flow 1.29 × 10−4 Ls−1; current density 2 mAcm2; pH = 3.0 | >99% | It has high efficiency, it requires little space, it is not selective and is easy to operate/it generates a large amount of metal-containing sludge [13]. |
| Pb2+ | Adsorption | Pb2+ = 50 mg·L−1; adsorbent: active carbon; pH = 6.0 | >85% | Effective and economic method; it is flexible in design and operation and besides it can produce high-quality treated effluent; easy metal recovery [14,15,16] |
| Pb2+ | Pb2+ = 50 mg·L−1; adsorbent: chitosan; pH = 4.5 | >60% | ||
| Cu2+ | Pb2+ = 10 mg·L−1; adsorbent: chitosan; pH = 4.5 | >80% |